Marin launches food scraps-to-energy program for restaurants

If you have a difficult time leaving food on your plate, your conscience will be relieved to learn that Marin has launched its first food scraps-to-energy program that turns leftover plant matter into renewable energy.

Marin Sanitary Service and the Central Marin Sanitation Agency unveiled a new joint program Tuesday — the second of its kind in the state — to a group of about 100 local business owners, elected officials and eco-conscious members of the public. Attendees watched as collected fruit and vegetable waste was ground up at Marin Sanitary Service in San Rafael and transported in a special truck down the street to the Central Marin Sanitation Agency where it is turned into energy.

Joe Garbarino, owner and operator of Marin Sanitary Service, said nearly 30 percent of the waste that goes to the landfill is food, so turning that waste into a usable resource helps the environment.

"We're mixing our solid waste with their liquid waste to create methane gas that is used as fuel to power the Central Marin Sanitation Agency's generator," Garbarino said. "We're diverting 20 tons of food waste each week."

The program began about six years ago when San Rafael received a $25,000 grant from Pacific Gas and Electric Co. to study the possibility of creating a food scraps-to-energy plan. After conducting a waste study and launching a pilot program, sanitation officials now have their sights set on expansion.

Kim Scheibly, with Marin Sanitary Service, said there's a dedicated food waste coordinator who works with the program's 35 restaurants and food vendors, including Whole Foods, United Markets, Scotty's Market, Marin Country Mart and Woodlands Market, but the plan is to add more participants.

The way the program works is restaurant workers place food waste in special carts that are picked up by Marin Sanitary Service drivers. The scraps are delivered to the transfer station, where they are ground into one-inch bits. The ground food is trucked to the Central Marin Sanitation Agency and dumped into a large vat, where it is combined with collected fats, oils and grease.

The oily mixture is then pumped into the agency's anaerobic digesters, where bacteria breaks down the concoction into methane biogas and biosolids. The methane is piped through a filter that removes impurities before it is run through a generator at the wastewater treatment facility. Leftover biosolids are used as landfill cover and will eventually be sold as compost.

Jason Dow, manager of Central Marin Sanitation Agency, said the agency has been able to increase its energy production from eight hours a day with just oils and fats to about 17 hours a day with the food scraps added in. Within two or three years he hopes to create more energy than the agency can use.

"We'll increase our generation to 24 hours per day and export excess energy back to the grid," Dow said.

Turning trash into treasure is not a cheap endeavor as $2.2 million has been invested in the program. Patty Garbarino, Marin Sanitary Service president, said the program will ultimately serve about 75 percent of the county and save the public money.

"We see it as a cost-savings because energy will no longer be needed from the grid for the Central Marin Sanitation Agency," she said.

For Neil Edgar, executive director of the California Compost Commission in Sacramento, seeing the program come to fruition is exciting because he did some of the original design and permitting work for Marin Sanitary Service.

"These are the kinds of projects we need to see happening all over the state," Edgar said. "We need to double the amount of composting we have to reach the 75 percent diversion goal (by 2020 for California) and ultimately zero waste."

Bill Carney, who heads Sustainable San Rafael, said he thinks most San Rafael businesses will opt to participate in the program.

"I think most enterprises want to do the right thing," Carney said. "I'm confident the vast majority of businesses will take advantage of the new system."

He said the next step is to get people to push for a similar residential program.

"I'd like to see it evolve into bringing in household food waste," Carney said.